Objectives and Strategies for Using Derivatives (Fair Value of Derivatives) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets	$ 61	$ 70
Liabilities	120	48
Designated as Hedging Instrument [Member]
Assets	48	29
Liabilities	93	28
Interest Rate Contract [Member]
Assets	16	24
Liabilities	75	2
Interest Rate Contract [Member] | Other current assets [Member] | Designated as Hedging Instrument [Member]
Assets	3	0
Interest Rate Contract [Member] | Other assets [Member] | Designated as Hedging Instrument [Member]
Assets	11	24
Interest Rate Contract [Member] | Accrued expenses [Member] | Designated as Hedging Instrument [Member]
Liabilities	44	0
Interest Rate Contract [Member] | Other liabilities [Member] | Designated as Hedging Instrument [Member]
Liabilities	31	2
Foreign Exchange Contract [Member]
Assets	45	46
Liabilities	33	39
Foreign Exchange Contract [Member] | Other current assets [Member] | Not Designated as Hedging Instrument [Member]
Assets	13	41
Foreign Exchange Contract [Member] | Other current assets [Member] | Designated as Hedging Instrument [Member]
Assets	25	4
Foreign Exchange Contract [Member] | Other assets [Member] | Designated as Hedging Instrument [Member]
Assets	9	1
Foreign Exchange Contract [Member] | Accrued expenses [Member] | Not Designated as Hedging Instrument [Member]
Liabilities	27	20
Foreign Exchange Contract [Member] | Accrued expenses [Member] | Designated as Hedging Instrument [Member]
Liabilities	6	16
Foreign Exchange Contract [Member] | Other liabilities [Member] | Designated as Hedging Instrument [Member]
Liabilities	0	3
Commodity Contract [Member]
Assets	0	0
Liabilities	12	7
Commodity Contract [Member] | Accrued expenses [Member] | Designated as Hedging Instrument [Member]
Liabilities	11	7
Commodity Contract [Member] | Other liabilities [Member] | Designated as Hedging Instrument [Member]
Liabilities	$ 1	$ 0